Mary Roach delights with talk on flatulence, rectums and other gassy topics

By Sheena Mcfarland And Ellen Fagg Weist The Salt Lake Tribune

Published April 23, 2014 11:36 am

"Gulp" • The author's newest book continues her trend of examining taboo subjects.

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This is an archived article that was published on sltrib.com in 2014, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Mary Roach has found beauty in one of the darkest and smelliest places on the planet  the human gut.

As part of her research for her newest book, "Gulp: Adventures on the Alimentary Canal," she underwent a colonoscopy sans drugs so she could explore her gastrointestinal tract.

"We're too busy looking at Christina Aguilera and so few people have seen their own organs," which are a human's most precious possessions, she told a crowd at the Salt Lake Public Library's Main Branch Monday night.

Roach read from archived medical journals about the amazing ability of the anal sphincter, which can differentiate among solid, liquid and gas, and whether the owner of that sphincter is alone or in company, and whether or not that person's pants are up or down.

Roach delights in delving into taboo topics, which previously have included decomposing bodies, sex and the afterlife.

She exalted the beauty of saliva and marveled at the storage capacity of the human rectum during her bookstore stop, which was hosted by Weller Bookworks.

Her ability to take complicated, technical science speak and turn it into accessible, humorous prose was clear as she spoke with the audience, taking questions on topics ranging from the ability to produce "blue darts"  farts that ignite that color due to methane production in the intestine  to whether she gassed up after eating a pint of beans at Beano headquarters  "I'm a producer. My husband, he's an executive producer."

In an email interview before Roach's visit, The Salt Lake Tribune's Ellen Fagg Weist asked Roach about that colonoscopy, researching the chapter on flatulence and the concept of "blaming the dog."

What inspired you to think there would be a book in the digestive tract?

In "Packing for Mars," I came across a study where there were a bunch of space researchers trying to see if man could survive on meals of dead bacteria. That made me think that the science behind eating would be as interesting as the food itself.

What chapter was the most fun to write?

The flatulence chapter was the most fun to write because there is a tremendous wealth of funny material. There is a lot of surprising creativity that went into the study of flatulence. How do you trap the gas? One answer to that is Mylar flatus-trapping pantaloons. There was a guy who studied flatulence in the 1960s whose name was Colin Leakey.

About that chapter, in which you introduce the concept of "blaming the dog": What did you learn from researchers who study flatulence?

People would be surprised to know that most of the gas produced, hydrogen and methane, has no smell at all. The offending culprits are hydrogen sulfide, which we can smell in 2 parts per million. It's a tiny, tiny portion of the gas that is produced. Most of it is not something you can smell. It is flammable, though, so that's one reason why when you have a colonoscopy they have to "clean you out." There have been cases where there have been explosions inside the colon, when there are still pockets of air left in. Not a good thing.

What was the most surprising to you in the reporting?

Reportingwise, I think the rectum chapter, which takes place at Avenal State Prison. [It was] fascinating because I've never spent time in a prison in that setting, so that was a particularly strange and interesting reporting experience.

The nose chapter was also surprising in that I did not really appreciate the extent to which we eat with our noses. People tend to think it's all in the mouth, but 80 percent of flavor is olfactory. There is a tremendous contribution made by the human nose.

What was most unusual about your experience viewing your innards while undergoing a "sedation-free colonoscopy"?

While it was occasionally painful, it was manageable pain. It was not nearly as big of a deal as I thought it would be. Really, it's your only opportunity to see the inside of your own colon. While [that] doesn't appeal to everyone, I thought it was pretty special. The colon is surprisingly pink and clean-looking. It's a bubble-gum pink, glistening, tidy place.

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